Method, system and apparatus for using ims communication service identifier

ABSTRACT

A method includes obtaining, by an HSS, information related to a user subscribed IMS communication service identifier, and sending information of a user subscribed IMS communication service identifier to a SID-requiring network entity according to the information related to the user subscribed IMS communication service identifier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application a continuation of U.S. patent application Ser. No. 12/539,890, filed on Aug. 12, 2009, which is a continuation of International PCT Application No. PCT/CN2007/071090, filed on Nov. 19, 2007. The International PCT Application claims priority to Chinese Patent Application No. 200710079246.2, filed on Feb. 13, 2007. The afore-mentioned patent applications are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The embodiments of this invention relate to the communication field and in particular to a method, system and apparatus for using IMS communication service identifiers in a communication system.

BACKGROUND OF THE INVENTION

In an existing IP Multimedia Subsystem (IMS) architecture of the 3GPP, most application services may be provided by an Application Server (AS). Provision of an application service for a user session by using a kind of AS is determined dependent upon an initial Filter Criteria (iFC) in a user service profile.

In the related art, a Cx interface is set between a Serving Call Session Control Function (S-CSCF) and a Home Subscriber Server (HSS).

The concept of IMS communication Service Identifier (SID) in an IMS domain, and thus defines application demands and a basic architecture for the SID. An important demand for using the SID is to identify each separate service.

In the related art, a network entity which needs to use the IMS communication service identifier cannot acquire any IMS communication service identifier and further cannot perform corresponding operations dependent upon the IMS communication service identifier.

SUMMARY OF THE INVENTION

Embodiments of the invention provide a method, system and apparatus for using an IMS communication service identifier so that a network entity which needs to use the IMS communication service identifier can acquire the IMS communication service identifier from an HSS.

The method according to an embodiment of the invention includes the steps of: getting, by a home location register HSS, arrival of information related to a user subscribed IMS communication service identifier; and, sending, by the HSS, information of a user subscribed IMS communication service identifier to a SD-requiring network entity according to the information related to the user subscribed IMS communication service identifier.

The system according to an embodiment of the invention includes: a home location register HSS, adapted to get arrival of information related to a user subscribed IMS communication service identifier and to send information of the user subscribed IMS communication service identifier to a network entity, which needs to use the IMS communication service identifier according to the information related to the user subscribed IMS communication service identifier; and, the network entity which needs to use the IMS communication service identifier is adapted to receive the information of the IMS communication service identifier sent from the HSS.

The home location register according to an embodiment of the invention includes: a storage module adapted to store information of a user subscribed IMS communication service identifier; a getting module adapted to get whether information related to the user subscribed IMS communication service identifier arrives; and, a sending module adapted to send information of the user subscribed IMS communication service identifier stored in the storage module to a SD-requiring network entity when the getting module determines the arrival of the information related to the user subscribed IMS communication service identifier.

The application server according to an embodiment of the invention includes: an application checking module adapted to determine whether an inquiry or subscription directed to an HSS is required for a provided service; a request sending module adapted to send to the HSS a message requesting for an inquiry about or subscription to information of an IMS communication service identifier when the application checking module determines that the inquiry or subscription directed to the HSS is required; and, a receiving module adapted to receive the information of the IMS communication service identifier sent from a network side.

The serving call session control function entity according to an embodiment of the invention includes: a receiving module adapted to receive information of an IMS communication service identifier sent from a network side; a storage module adapted to store the information of the IMS communication service identifier; and, an updating module adapted to update data stored by the storage module using the information of the IMS communication service identifier received by the receiving module.

In the embodiments of the invention, the HSS sends the information of the information of the user subscribed IMS communication service identifier to the network entity which needs to use the IMS communication service identifier upon getting arrival of the information of the user subscribed IMS communication service identifier, so that the network entity which needs to use the IMS communication service identifier can acquire the IMS communication service identifier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of the method according to the embodiments of the invention;

FIG. 2 shows an implementing mode of storing an IMS communication service identifier in user service profile information according to an embodiment of the invention;

FIG. 3 shows an implementing mode of storing an IMS communication service identifiers in user service profile information according to an embodiment of the invention;

FIG. 4 is a signaling flow chart according to an embodiment of the invention;

FIG. 5 is a signaling flow chart according to an embodiment of the invention;

FIG. 6 is a signaling flow chart according to an embodiment of the invention;

FIG. 7 is a schematic diagram of a system according to an embodiment of the invention;

FIG. 8 is a schematic diagram of a home location register according to an embodiment of the invention;

FIG. 9 is a schematic diagram of an application server according to an embodiment of the invention; and

FIG. 10 is a schematic diagram of a service call session control function entity according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Each separate IMS communication service can be identified after an introduction of the SID, as the SID in current standards is part of an iFC, and the iFC is primarily intended for triggering implementation of a certain application in an AS but not for checking subscription for a service. Consequently, the above approach can satisfy neither a demand of an S-CSCF for checking a subscribed service nor a demand of an AS for an inquiry and subscription of a subscribed service.

The embodiments of this invention provide a method for using an IMS communication service identifier in a communication system according to an embodiment of the invention so that a network entity which needs to use the IMS communication service identifier can acquire the IMS communication service identifier. In the embodiments of the invention, the network entity which needs to use the IMS communication service identifier may also be called as a SID-requiring network entity. The method as illustrated in FIG. 1 may include the following processes.

In block S1: An HSS gets arrival of information related to a user subscribed IMS communication service identifier.

The following scenarios may exist dependently upon different network entities which need to use the IMS communication service identifier and upon different times at which information related to the user subscribed IMS communication service identifiers arrive.

In the first scenario, an S-CSCF is the SD-requiring network entity sends to the HSS a message requesting for downloading a user service profile. The HSS determines the arrival of the information upon reception of the message requesting for downloading the user service profile.

In the second scenario, an S-CSCF is the SID-requiring network entity. The HSS determines arrival of the information upon change of the information of the user subscribed IMS communication service identifier. The IMS communication service identifier is stored in the HSS. The arrival of the information may refer to the arrival of a time to send the IMS communication service identifier.

In the third scenario, an AS is the SD-requiring network entity. The AS determines whether to send a message requesting for an inquiry to the HSS according to provided services. For instance, an application provided by the AS needs to use one or more IMS communication service(s), the AS inquires of the HSS about whether the user has subscribed to the service(s). The AS inquires of the HSS to obtain a list of the user subscribed IMS communication service identifier. Alternatively, the AS may send the message requesting for the inquiry to the HSS directly. The HSS determines the arrival of the information upon reception of the message requesting for the inquiry.

In the fourth scenario, the AS is the SID-requiring network entity. The HSS determines the arrival of the information upon change of the information of the user subscribed IMS communication service identifier. The IMS communication service identifier is stored in the HSS. The arrival of the information may refer to the arrival of a time to send the IMS communication service identifier.

In block S2: The HSS sends the information of the user subscribed IMS communication service identifier to the SID-requiring network entity.

An IMS communication service identifier can be used in the HSS as follows: the IMS communication service identifier is used to specify a condition for triggering the AS in an iFC, and to specify which specific application of the AS is to be performed; the IMS communication service identifier may be used to indicate authorization for a subscribed service of a core network, it corresponds to an IMS Public User Identifier (IMPU) or IMPUs in the user service profile information and is indicative of a subscribed IMS communication service. The IMPU(s) may be a SIP URI or a Tel URI. If the IMS communication service identifier may be used to indicate authorization for a subscribed service of a core network, storage of the IMS communication service identifier in the user service profile information may be implemented in the following two ways: as illustrated in FIG. 2, a data module is added newly in the user service profile information stored in the HSS, so as to store the information of the user subscribed IMS communication service identifier; or as illustrated in FIG. 3, media subscription information stored in the user service profile information stored in the HSS may be replaced by the information of the user subscribed IMS communication service identifier.

For the HSS sending the information of the user subscribed IMS communication service identifier to the SID-requiring network entity in accordance with the first scenario, the HSS carries the information of the user subscribed IMS communication service identifier in a response message, and sends the response message to the S-CSCF.

In accordance with the second scenario, the HSS sends the updated information of the user subscribed IMS communication service identifier to the S-CSCF which needs to use the IMS communication service identifier, and the S-CSCF provides the services for the user.

In accordance with the third scenario, the HSS carries the information of the user subscribed IMS communication service identifier in a response message, and sends the response message to the AS.

In accordance with the fourth scenario, the HSS sends the updated information of the user subscribed IMS communication service identifier to the AS having subscription relation with a changed IMS communication service identifier. During establishment of the subscription relationship, the AS may determine whether to send a message requesting for the subscription to the HSS according to the requirement of the application. The AS sends the message requesting for subscription to the HSS to establish the subscription relationship when there is a need of subscribing to the IMS communication service identifier. For instance, a change in the list of the user subscribed IMS communication service identifier may cause the subscription to be changed from supporting provision of the application to not supporting provision of the application. Therefore the AS needs to subscribe to the change of the services from the HSS by sending a request for subscribing to the list of the identifiers of IMS communication services to the HSS.

The method may also include the following process.

In block S3: The SID-requiring network entity performs corresponding operations dependent upon the acquired IMS communication service identifier.

In accordance with the first and second scenarios, as obtaining the information of the user subscribed IMS communication service identifier, the S-CSCF performs an IMS communication service authorization check for a session during set-up of the session. The S-CSCF may match the information of the user subscribed IMS communication service identifier obtained from the HSS with the information of the IMS communication service identifier carried in a session set-up request. If the information of the IMS communication service identifier carried in the session set-up request exists in the information of the user subscribed IMS communication service identifier obtained from the HSS, it is considered that the IMS communication service authorization check is passed; otherwise a failure response is returned. There may be a particular situation in which the IMS communication service identifier information carried in the session set-up request is null, then it may be considered that the IMS communication service authorization check is passed.

In accordance with the third and fourth scenarios, the AS obtains the information of the user subscribed IMS communication service identifier, and the AS performs a logic process, which logic process may include a check of an association relation between the application and the user subscribed IMS communication service.

Detailed descriptions may be presented below in embodiments as follows.

In an embodiment, the S-CSCF is the network entity which needs the IMS communication service identifier. After successful user registration, the S-CSCF sends a message for requesting for downloading the user profile information to the HSS via the Cx interface. The HSS returns in a response message the user profile information including the list of the identifiers of user subscribed IMS communication services. After the user registration has been finished, upon change of the user profile information the HSS may be sent an informing message to the S-CSCF serving the user to inform the change of the user profile information via the Cx interface, and the updated user profile information may be carried in the informing message, and the updated user profile information may include the list of the identifiers of user subscribed IMS communication services. As receiving the user profile information, the S-CSCF may store locally the profile including the list of the identifiers of user subscribed IMS communication services, and perform an IMS communication service authorization check for set-up session dependent upon the IMS communication service identifier. The set-up session may include a session set up with a calling UE (User Equipment) or a session set up with a called UE. This embodiment takes a calling UE as an example. The situation of a called UE is similar. The S-CSCF serving the called UE may perform the authorization check. With reference to FIG. 4, the embodiment includes the following processes.

In processes 1˜2, a session request is initiated by a UE, and the session request is routed to the S-CSCF through a Proxy Call Session Control Function (P-CSCF).

In process 3, the S-CSCF checks whether the user subscribes to a corresponding IMS communication service. If the user subscribes to a corresponding IMS communication service, the calling set-up is continued, and processes 4˜5 may be skipped; otherwise, the subsequent processes are carried out.

In processes 4˜5, the S-CSCF returns to the UE a prohibition response through the P-CSCF. The prohibition response indicates a refusal reason that the user does not subscribe to the service.

In an embodiment, the IMS communication service identifier is used in a flow of activating a Personal Network Management (PNM) service. The embodiment as illustrated in FIG. 5 includes:

In the process 1, a PNM UE sends an activation request to a Network Application Entity (NAF) via a Ut interface. The activation request may carry one or more information as follow: an IMPU, an activated type, a service code and a priority parameter.

In the process 2, the NAF authenticates an identity of the PNM UE. As the authentication has been passed, an IP Multimedia Private Identifier (IMPI) of the PNM UE is added in the request message. The request message may be forwarded to a PNM AS. The PNM AS checks whether IMPI-IMPU-PNID has been recorded locally in the PNM AS to determine whether the PNM UE has been registered with the PN (Personal Network).

In process 3, the PNM AS inquires an HSS to obtain information of all IMS communication services subscribed for the IMPU to be activated. It is implemented through an sh-Pull message in this embodiment.

The AS capable of inquiring the HSS may be an AS with a privilege so as to protect the safety of user information. An sh-Pull-Rep message may be used in this embodiment.

In process 4, the HSS returns in a response all the IMS communication services subscribed for the IMPU, the IMS communication services may be indicated by a list of IMS communication service identifiers (SID). The PNM AS compares the IMS communication service identifier carried in the activation request with the SID list downloaded from the HSS, and saves an intersection set of the both as services that can be activated. If there is no such an intersection set, an activation failure response may be returned. An sh-Pull-Rep message may be used.

In processed 5˜6, the PNM AS obtains capability information of the activated UE1 from an entity for storing the information capability of a UE.

In process 7, the PNM AS compares the capability information of the activated PNM UE with a capability required for a service to be activated. If a service requirement can be satisfied, the service is considered to be activated successfully by the PNM UE with the IMPU. The PNM AS saves the service activation setting information, and also possibly overwrites a previous activation profile if necessary. A successful activation record may include IMPI-IMPU-PNID, an activation type, a SID, a media component, and priority parameters, and the media component or the priority parameters may be null.

In process 8, the PNM AS sets in the HSS a subscription identifier of the subscription information associated with the IMPU, which subscription identifier carries an address of the PNM server. When the list of the SID(s) subscribed for the IMPU changes, the HSS may inform the PNM AS, and the PNM AS determines whether to modify the activation information.

The AS capable of subscribing to the change of the information of all associated IMS communication services subscribed for the IMPU may be an AS having a privilege, so as to protect the safety of the user information.

In process 9, the HSS returns to the PNM AS a response to setting of the subscription identifier.

In process 10, the PNM AS returns to the PNM UE an activation response indicating whether the present activation operation succeeds. In this embodiment, it is allowable to activate successfully part of services in the activation request. Therefore, an activation response message may carry the IMS communication service identifiers and the IMPUs of the services activated with success.

The embodiment as follow involves a deactivation operation of the PNM AS due to the change of the list of IMS communication service identifiers. The embodiment as illustrated in FIG. 6 includes the following processes.

In process 1, a user subscribed IMS communication service changes, for example, the SID list changes.

In process 2, the HSS informs the PNM AS. The PNM AS has performed a subscription operation dependent upon previous subscription. The process may be implemented by an sh-Notif message.

In process 3, the PNM AS returns a response to the HSS upon reception of the notification. The process may be implemented by an sh-Notif Resp message.

In process 4, the PNM AS determines whether to perform the deactivation operation according to the change of the SID. The PNM AS may delete an activation record.

In processes 5˜6, if all activation records associated with an IMPU are deleted, the PNM AS may revoke both a registration status associated with the IMPU and the subscription to the list of subscribed IMS communication services. As receiving the revoke of the PNM AS, the HSS deletes the subscription identifier and returns a response message. If there is any activation record regarding the IMPU remaining in the PNUM AS, the processes 5˜6 may be skipped.

In processes 7˜8, the user is notified that the deactivation operation is initiated by the network, and returns a response indicating reception of the notification.

It should be noted that any mechanism, including but not limited to OMA Push or MESSAGE in the SIP, can be used to perform the notification.

The embodiments of the invention also provide a system for using an IMS communication service identifier in a communication system as illustrated in FIG. 7. The system includes a home location register HSS and a SID required network entity connected to the HSS, the SID required network entity needs to use the IMS communication service identifier.

The HSS is adapted to sense the arrival of the information related to the identifiers of user subscribed IMS communication services, and send the locally stored information of the user subscribed IMS communication service identifier to the SID-requiring network entity.

The SID-requiring network entity is adapted to receive the information of the IMS communication service identifier sent from the HSS.

Further, the SID-requiring network entity is an S-CSCF, and a Cx interface is set between the S-CSCF and the HSS. The following two scenarios may be present dependent upon the different times at which the information related to the user subscribed IMS communication service identifier arrives.

The S-CSCF sends a message requesting for downloading a user service profile to the HSS via the Cx interface. Upon reception of the message requesting for downloading the user service profile, the HSS determines the arrival of the information, sends a response message of the message requesting for downloading the user service profile to the S-CSCF, wherein the information of the user subscribed IMS communication service identifier is contained in the response message.

The HSS determines the arrival of the information (which may refers to arrival of a time to send the IMS communication service identifier) when the information of the identifiers of the user subscribed IMS communication services changes, and sends the updated information of the user subscribed IMS communication service identifier to the S-CSCF which needs to use the IMS communication service identifier.

The S-CSCF which needs to use the IMS communication service identifier is further adapted to perform an IMS communication service authorization check for a newly set-up session by using the acquired information of the user subscribed IMS communication service identifier.

The IMS communication service authorization check is performed through the process of: matching, by the S-CSCF, the information of the user subscribed IMS communication service identifier acquired from the HSS, and information of an IMS communication service identifier carried in a session setting-up request, and, passing the IMS communication service authorization check if the information of the user subscribed IMS communication service identifier acquired from the HSS comprises the information of the IMS communication service identifier carried in the session setting-up request.

Further, the SID-requiring network entity is an AS, and an Sh interface is set between the AS and the HSS. The following two scenarios may be present dependent upon different times at which the information related to the user subscribed IMS communication service identifier arrives.

The AS sends to the HSS via the Sh interface a message requesting for an inquiry. The AS may firstly check a demand of a provided service and determine whether to send a message requesting for the inquiry to the HSS dependent upon the result of the check. For instance, if one or more IMS communication services need to be used by the application provided by the AS, the AS shall inquire of the HSS about whether the user has subscribed to the services through inquiring of the HSS about a list of identifiers of user subscribed IMS communication services. There are possibly other situations in which the message requesting for the inquiry needs to be sent to the HSS. The HSS determines arrival of the information upon reception of the message requesting for the inquiry, carries in a response message the locally stored information of the user subscribed IMS communication service identifier and sends the response message to the AS.

The HSS determines the arrival of the information, which arrival refers to the arrival of a time to send the IMS communication service identifier, when the locally stored information of the user subscribed IMS communication service identifier changes, and sends the updated information of the user subscribed IMS communication service identifier to the AS having a subscription relation with the a changed IMS communication service identifier. During establishment of the subscription relation, the AS may firstly check the demand of the provided service and determine whether to send a message requesting for subscription to the HSS dependent upon the result of the check. For instance, a change of the list of identifiers of user subscribed IMS communication services may cause the subscription to be changed from supporting provision of the application to not supporting provision of the application. Therefore, the AS shall subscribe to the change of the services from the HSS by sending to the HSS a request for subscribing to the list of identifiers of IMS communication services. There may exist other situations in which a message requesting for subscription needs to be sent to the HSS.

The network entity AS which needs to use the IMS communication service identifier is further adapted to perform an application logic process by using the acquired information of the user subscribed IMS communication service identifier.

The embodiments of the invention further provide a home location register including a storage module, a sensing module and a sending module coupled with the storage module and the sensing module, as illustrated in FIG. 8.

The storage module is adapted to store the information of identifiers of user subscribed IMS communication services. The storage module may store both the information of the user subscribed IMS communication service identifier and media subscription information, or store only the information of the user subscribed IMS communication service identifier.

The sensing module is adapted to sense whether the information related to identifiers of user subscribed IMS communication services arrives.

The sending module is adapted to send the information of the user subscribed IMS communication service identifier stored in the storage module to a SD-requiring network entity, when the sensing module determines arrival of the information.

The embodiments of the invention further provide an application server including an application checking module, a request sending module coupled with the application checking module, a receiving module, and a logic determining module coupled with the receiving module, as illustrated in FIG. 9.

The application checking module is adapted to determine whether a provided application needs to make an inquiry or subscription directed to an HSS.

The request sending module is adapted to send to the HSS a message requesting for an inquiry about or subscription to information of IMS communication service identifier when the application checking module determines that the inquiry or subscription to the HSS is needed.

The receiving module is adapted to receive the information of the IMS communication service identifier sent from a network side.

The logic determining module is adapted to determine an association relationship between the provided application and the information of the IMS communication service identifier dependent upon the information of the IMS communication service identifier received by the receiving module.

The embodiments of the invention further provide a Serving Call Session Control Function entity including a receiving module, a storage module, an updating module respectively coupled with the receiving module and the storage module, and an authorization checking module coupled with the storage module, as illustrated in FIG. 10.

The receiving module is adapted to receive information of an IMS communication service identifier sent from a network side.

The storage module is adapted to store the information of the IMS communication service identifier.

The updating module is adapted to update data stored by the storage module by using the information of the IMS communication service identifier received by the receiving module.

The authorization checking module is adapted to perform, during set-up of a session, an IMS communication service authorization check for the session by using the information of the IMS communication service identifier currently stored by the storage module.

In the embodiments of the invention, the HSS sends the locally stored information of the user subscribed IMS communication service identifier to the SD-requiring network entity upon sensing the arrival of the information related to the user subscribed IMS communication service identifier. Thus, the SID-requiring network entity acquires the IMS communication service identifier.

Further, the S-CSCF acts as the SID-requiring network entity. After acquiring the IMS communication service identifier, the S-CSCF performs the IMS communication service authorization check for a session during set-up of the session, thereby precisely ensuring legality of the set-up of the session.

Further, the AS acts as the SID-requiring network entity. After acquiring the IMS communication service identifier, the AS may perform the application logic process dependent upon the IMS communication service identifier, which process includes but is not limited to checking the association relation between the application and the user subscribed IMS communication services, thereby ensuring legality of the implemented application.

Although the above embodiments of the present invention have been described in the context of the IMS network, the embodiments of the present invention are also applicable to similar multimedia subsystems such as MMD (Multimedia Domain).

Evidently, those skilled in the art can make various changes and variations to the invention without departing from the spirit and scope of the invention. The invention is intended to encompass these changes and variations provided they fall within the appended claims and equivalents thereof. 

1. A method for using a service identifier (SID) in an IP Multimedia Subsystem (IMS) network, comprising: obtaining, by a home location register (HSS), information related to a user subscribed SID; and sending, by the HSS, the SID to a network entity according to the information related to the SID; wherein the SID is for identifying an IMS service, and the network entity performs operations according to the SID.
 2. The method according to claim 1, wherein the network entity includes a Serving Call Session Control Function (S-CSCF); the HSS determines arrival of the information related to the SID upon reception of a message requesting for downloading a user service profile from the S-CSCF; and the HSS sends a response message of the message requesting for downloading the user service profile to the S-CSCF; wherein the SID is contained in the response message.
 3. The method according to claim 1, wherein the network entity includes an S-CSCF; the HSS determines arrival of the information related to the SID when the information of the SID is updated; and the HSS sends the updated SID to the S-CSCF.
 4. The method according to claim 1, wherein the network entity includes an S-CSCF, and operations performed by the network entity include an IMS communication service authorization check for a session during setting up the session.
 5. The method according to claim 4, wherein the IMS communication service authorization check is performed by following manner: matching, by the S-CSCF, the SID obtained from the HSS, with IMS communication service identifier carried in a session setting-up request; and the IMS communication service authorization is successful if the SID acquired from the HSS comprises the IMS communication service identifier carried in the session setting-up request.
 6. The method according to claim 1, wherein the SID is stored in a user service profile in the HSS.
 7. The method according to claim 1, wherein the network entity includes an application server (AS); the HSS determines arrival of the information related to the SID upon reception of an inquiry message from the AS; and the HSS sends a response message containing the SID to the AS.
 8. The method according to claim 1, wherein the network entity includes an AS; the HSS determines arrival of the information related to the SID when the SID is updated; and the HSS sends the updated SID to the AS, wherein the AS has a subscription relationship with a changed IMS communication service identifier.
 9. A home location register (HSS), comprising a processor configured to perform the following method: obtaining, information related to a user subscribed service identifier (SID); and sending, the SID to a network entity in an IP Multimedia Subsystem (IMS) network according to the information related to the SID; wherein the SID is for identifying an IMS service, and the network entity performs operations according to the SID.
 10. The HSS according to claim 9, wherein the network entity includes a Serving Call Session Control Function (S-CSCF); the HSS determines arrival of the information related to the SID upon reception of a message requesting for downloading a user service profile from the S-CSCF; and the HSS sends a response message of the message requesting for downloading the user service profile to the S-CSCF; wherein the SID is contained in the response message.
 11. The HSS according to claim 9, wherein the network entity includes an S-CSCF; the HSS determines arrival of the information related to the SID when the information of the SID is updated; and the HSS sends the updated SID to the S-CSCF.
 12. The HSS according to claim 9, wherein the network entity includes an S-CSCF, and operations performed by the network entity include an IMS communication service authorization check for a session during setting up the session.
 13. The HSS according to claim 12, wherein the IMS communication service authorization check is performed by following manner: matching, by the S-CSCF, the SID obtained from the HSS, with IMS communication service identifier carried in a session setting-up request; and the IMS communication service authorization is successful if the SID acquired from the HSS comprises the IMS communication service identifier carried in the session setting-up request.
 14. The HSS according to claim 9, wherein the SID is stored in user service profile in the HSS.
 15. The HSS according to claim 9, wherein the entity includes an application server (AS); the HSS determines arrival of the information related to the SID upon reception of an inquiry message from the AS; and the HSS sends a response message containing the SID to the AS.
 16. The HSS according to claim 9, wherein the network entity includes an AS; the HSS determines arrival of the information related to the SID when the information of SID is updated; and the HSS sends the updated SID to the AS, wherein the AS has a subscription relationship with a changed IMS communication service identifier.
 17. A network entity in an IP Multimedia Subsystem (IMS) network, comprising a processor configured to perform following method: receiving a user subscribed service identifier (SID) from a home location register (HSS) upon the HSS determines arrival of information related to the SID; performing operations according to the SID wherein the SID is used to identify an IMS service.
 18. The network entity according to claim 17, wherein the network entity includes a Serving Call Session Control Function (S-CSCF); the HSS determines arrival of the information related to the SID upon reception of a message requesting for downloading a user service profile from the S-CSCF; and the HSS sends a response message of the message requesting for downloading the user service profile to the S-CSCF; wherein the SID is contained in the response message.
 19. The network entity according to claim 17, wherein the network entity includes an S-CSCF; the HSS determines arrival of the information related to the SID when the information of the SID is updated; and the HSS sends the updated SID to the S-CSCF.
 20. The network entity according to claim 17, wherein the network entity includes a S-CSCF, and operations performed by the network entity include an IMS communication service authorization check for a session during setting up the session.
 21. The network entity according to claim 20, wherein the IMS communication service authorization check is performed by following manner: matching, by the S-CSCF, the SID obtained from the HSS, with IMS communication service identifier carried in a session setting-up request; and the IMS communication service authorization is successful if the SID acquired from the HSS comprises the IMS communication service identifier carried in the session setting-up request.
 22. The network entity according to claim 17, wherein the SID is stored in user service profile in the HSS.
 23. The network entity according to claim 17, wherein the entity includes an application server (AS); the HSS determines arrival of the information related to the SID upon reception of an inquiry message from the AS; and the HSS sends a response message containing the SID to the AS.
 24. The network entity according to claim 17, wherein the network entity includes an AS; the HSS determines arrival of the information related to the SID when the information of SID is updated; and the HSS sends the updated SID to the AS, wherein the AS has a subscription relationship with a changed IMS communication service identifier. 